Three resin lots required for part qualification

[iautry1973]

I have never had to run three lots of resin, but I am guessing it is to prove the process is stable with changing lots of material. If it isn't something that is a super critical part I would just let the customer know the normal process and that any additional testing costs extra. Found a lot of times customers rethink things when they realize their requirements cost them money.

[JayDub]

I work for a medical molder (regulated facility) and we write our PQ protocols to use multiple material lots "if available". The idea of PQ is to model long term behavior of the process and prove it's stable, so varying material is a good challenge. It works fine when using obscure medical grades of engineering resins that come in 50 lb sacks, but for commodities like olefins that you have to buy by the Gaylord (which for small parts may be a ten year supply), it's just not feasible. For HIPS, it would be insane.